It is certainly a not so rare scenario that especially in life science or chemistry a broadly worded claim (broad formulas or wording) also covers embodiments which are not working. “Not working” in the sense of Art. 83 EPC has to be understood that these embodiments do not fulfill a functional or other limitation which is part of the claim itself. If the not-guaranteed function or characteristics is not part of the claim, the “non-working examples” or better “examples which do not have the desired benefit” can rarely be attacked under Art. 83 EPC, but potentially under Art. 56 (lack of inventive step) as then they do not produce the desired advantage.

The decision T175/15-3.3.10 issued by the Boards of Appeal on July 5, 2018 now gives some guidance as how to deal with such issue:

In the decided opposition case it has been acknowledged by the patent proprietor that the claim (directed on a luminescent material and having a chemical formula) does cover examples which do not produce the effect also mentioned in the claim, i.e. the production of white light.

The Board on this decision has now summarized important aspects as how to deal with such a scenario.

  • In the present case the Board found that, due to the breadth of the general formula in claim 1, the preparation of compositions falling within the formula, and testing whether or not they have the properties required by claim 1, constitutes an undue burden for the skilled person.


  • The patent did indicate in a general manner that finely controlling amounts and proportions of substrates, agents, etc. could lead to the desired result. However, no specific instructions had been given in the patent and how to exercise such control of the resulting properties.


  • The Board held that the burden of proof is on the side of the patent proprietor that the failure of success with regard to certain examples falling under a claim can be turned into a success by the skilled person without inventive step:


The Board especially pointed out that the respondent (patent proprietor) had not cited any evidence to show that at the date of filing a skilled person knew how to predict whether or not the claimed effect would occur. The state of the art did not give the missing teaching, either.


  • The Board held that the claim had been more an invitation to perform a research program aimed at finding materials with the desired properties.


  • Most importantly, the Board also dealt with the elder decision T292/85, according to which an invention had been regarded as sufficiently disclosed if at least one way was clearly indicated enabling the skilled person to carry out the invention. The issue before the Board in T292/85 was whether the non-availability of some variants fulfilling the functional definition required by the invention had an effect on its sufficiency, which the Board denied in this elder case. The Board in the present case decided that the issue underlying the present case had been whether or not the skilled person had been in a position to identify, among the compounds of the (broad) general formula of claim 1, those which fulfill the functional definition it requires. The Board thus decided that the situation in the present case had not been comparable to that at issue in T292/85.